A:种植园经济的发展和奴隶贸易的进行致使黑种人口剧增
B:对现代文明的不适应,导致土著人口骤减
C:欧洲移民源源而来,导致黑色人种的数量大幅度增加
D:赋税政策调整和高产粮食作物的引种使人口总数大幅度上升
蛔虫在人体的小肠内不会被消化的原因是( )
地理环境各要素在南北方向产生有规律更替的主要原因是( )
根据短文内容判断下列句子正误。
Look! It's my school dining hall.We are here for lunch every day.Before,there were many tall trees.Ten years ago,there was only a small house in my school.There was no library or computer.The playground was also small.
Now,my school is very beautiful.The playground is big.The grass is green.We have PE and play sports on it.There is a nice teaching building in my school.It has six floors.The computer rooms are on the fourth floor and the library is on the sixth floor.We read books in the library and use the Internet in the computer rooms.
“大江东去,浪淘尽,千古风流人物。故垒西边,人道是,三国周郎赤壁。乱石穿空,惊涛拍岸,卷起千堆雪。江山如画,一时多少豪杰。”
请回答: